t_stat fp_unpack (uint32 ad, FPA *fp)
{
uint8 d0, d1, esign;
esign = M[ad] & FLAG; /* get exp sign */
d0 = M[ad] & DIGIT; /* get exp lo digit */
MM (ad);
if ((M[ad] & FLAG) == 0) /* no flag on hi exp? */
return STOP_FPMF;
d1 = M[ad] & DIGIT; /* get exp hi digit */
MM (ad);
fp->addr = ad; /* save mant addr */
if (BAD_DIGIT (d1) || BAD_DIGIT (d0)) /* exp bad dig? */
return STOP_INVDIG;
fp->exp = ((d1 * 10) + d0) * (esign? -1: 1); /* convert exponent */
fp->sign = (M[ad] & FLAG)? 1: 0; /* get mantissa sign */
return fp_scan_mant (fp->addr, &(fp->lnt), &(fp->zero));
}
int32 dp_cvt_ad (uint8 *ap)
{
int32 i, r;
uint8 c;
for (i = r = 0; i < DP_ADDR; i++, ap++) { /* loop thru addr */
c = *ap & DIGIT; /* get digit */
if (BAD_DIGIT (c)) /* bad digit? */
return -1;
r = (r * 10) + c; /* bcd to binary */
}
return r;
}
int32 dp_cvt_bcd (uint32 ad, int32 len)
{
uint8 c;
int32 r;
for (r = 0; len > 0; len--) { /* loop thru char */
c = M[ad] & DIGIT; /* get digit */
if (BAD_DIGIT (c)) /* invalid? */
return -1;
r = (r * 10) + c; /* cvt to bin */
PP (ad); /* next digit */
}
return r;
}
